QUESTION BANK GENERAL ENGINEERING KNOWLEDGE PART-3

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Q a) With reference to fatigue of engineering components explain the influence of stress level at cyclical frequency on expected operating life.

b) Explain the influence of the material defects on the safe operating life of the engineering component.

c) State the factors which influence the possibility of the fatigue cracking of a bed-plate transverse girder & explain how the risk of such cracking can be minimized.

Q a) Briefly explain the term metal fatigue and further explain how fatigue failure occurs.

b) State the difference between high stress/low cycle & low stress/high cycle fatigue giving an example of each.

c) State how defects in the metal can influence the expected safe life of a component.

d) State how fuel injection timing & cylinder power balance can influence the possibility of fatigue cracks developing in the bedplate.

Q a) Explain the causes of the formation of mill scale on steel plate.

b) Describe the preparation required before the application of conventional paints to the underwater surface of the hull.

c) Describe a coating scheme for the underwater hull using conventional paints.

Q Describe in detail each of the following processes giving example in each case where these are likely to occur in  the marine engineering:

a) Corrosion fatigue

b) Stress corrosion

c) Creeping cracks

d) Casting cracks

Q State with reasons how cracking in each of the following location is caused, rectified & avoided

a) ‘A’ frame

b) Bedplate longitudinal girder

c) Bed plate transverse girder

Q Discuss the causes of corrosion & the means by which corrosion of the following may be limited by manufacturers & ship’s personnel respectively:

a) Internal and external surfaces of auxiliary steam lines.

b) External surfaces of auxiliary boilers.

c) Water boxes of seawater coolers and condensers.

d) Main seawater inlet pipes.

Q Sketch suitable welded joints indicating the approximate plate thickness & dimensions of preparation for the following purposes:

(a) End plate connection to the shell of an unfired pressure vessel.

(b) Longitudinal seam of an unfired pressure vessel.

(c) Prefabricated combustion chamber for an auxiliary boiler.

Q a) Explain the action of each of the following metallurgical mechanisms:

i. Creep

ii. Brinelling

iii. Fretting

iv. Fretting corrosion

b) State, with reasons, where each of the mechanisms in (a) may occur in ship propulsion System.

Q Write short notes on (a) Optical and (b) Acoustic methods of non-destructive testing

Q a) State, with reasons, the causes of fatigue cracking of engineering components.

b) State, with reasons, how material and design defects can influence fatigue life.

c) With reference to engine bed plate transverse girders explain how the incidence of the fatigue cracking can be minimized.

Q a) Define the cause and effect of thermal stressing in cylinder heads, liners and pistons

b) Explain why thermal stressing is aggravated with increase in cylinder bore

c) Explain how stress concentration and its effect is relieved by maintenance & operational practices

Q Compare the following methods of crack detection, defining their advantages and limitations:

a) Radiographic

b) Ultrasonic

c) Magnetic

d) Dye penetrant

Q Various tests are carried out on material used for boiler construction. With reference to these tests, explain the following terms:

a. Elongation

b. Yield point

c. Area reduction

d. Ultimate stress

Q With reference to hydraulic system for deck machinery identify:

a) The types of contamination likely to be found in hydraulic systems for the deck machinery

b) The sources of such impurities

c) Means used to prevent problems with the contamination.

d) Possible effects of the oil contamination on the system.

e) Measure to be taken to deal with any contamination in the hydraulic system.

Q a) Sketch a watertight door and frame showing the manner of attachment to the bulkhead & the additional reinforcement carried by the bulkhead to compensate for the aperture.

b) Explain how water tightness of the door & frame mating surfaces is ensured with hydrostatic pressure tending to force the faces apart.

c) i. Describe the means of closing the door.

ii. State the number of closing stations and the position of each.

Q Describe the possible faults which may be found during a dry-dock inspection of the following:

a) Stern frame

b) Sea chest

c) Bilge keel

d) Anodes

e) Rudders

Q An auxiliary engine exhibits a tendency to hunt to such an extent that the engine speed variation prohibits the connection of the machine to the switchboard.

a) Discuss the possible causes of the hunting.

b) Explain how the problem of the hunting can be rectified.

Q Sketch and describe a stockless anchor illustrating the method or device used to attach it to the chain cable. When the anchor & cable are ranged during the ships underwater survey what parts require special attention & what defects are likely to be discovered?

Q What is understood by risk on board a ship? As a 2/E discuss various methods for hazard identification & assessment of the risks available on board.

Q a) Describe a vacuum sewage system

b) With reference to the system describe in (a):

i. State one advantage of the system

ii. State why a holding tank may be required to be fitted to the system

iii. State the problems resulting from the retention of the untreated sewage in a holding tank

Q What are the conditions required in the cylinders of a marine diesel engine for good combustion. Under normal working conditions how the following may occur:

a) Black smoke

b) White smoke

c) Blue smoke

What may be the suspect cause for each case to occur? What would be the remedy for it?

Q Sketch an automatic sprinkler system for combating fire in passenger spaces on a ship and state:

a) The safety devices incorporated in the system.

b) How the system is charged

c) The parameters governing the volume of the pressure tank

d) Means provided to prevent the passage of the seawater into the pressure tank

Q An engine room is operating in the unmanned (UMS) mode. In the event of a failure of the UMS system, explain the arrangements a 2/E officer should introduce to operate the machinery in manual mode for a passage of 10 days duration.

Q Explain in detail the circumstances under which as Interim DOC & an Interim SMC may be issued, what checks are necessary before each of these certificates are issued.

Q With reference to an emergency source of electrical power in passenger ships:-

a) Describe a typical power source.

b) Give a typical list of essential services which must be supplied simultaneously.

c) Explain how the emergency installation can be periodically tested

Q a) Describe the preparation necessary before the application (in dry dock) of sophisticated or approved long life coating to the underwater surface of the hull.

b) State the significance of the roughness profile.

c) List the different sophisticated coatings which are available.

Q With reference to lifeboats, describe with the help of the sketches:

a) The mechanism/handbrake used for lowering & state how it may be tested

b) The centrifugal brake & state the method of testing

c) Life boat servicing requirements & intervals for life boat wire falls renewal as per SOLAS 74.

Q With reference to fixed installations for dealing with a machinery space fire:

a) Describe with the help of a sketch a typical installation;

b) Explain the testing procedure for the equipment:

c) Outline the testing procedure for;

i. Remote shut down;

ii. Other equipment to be used in the event of an engine room fire.

Q Describe a bilge system suitable for a ship with cellular double bottoms. By means of a simple sketch, show the positions of pumps, manifolds, suctions, etc.

Q What preventative measures should be taken against the outbreak of fire in an oil burning vessel? How would you proceed to subdue such an oil fire? Describe with the help of a sketch, a foam type portable fire extinguisher.

Q Explain as per IMO how Green House Gas emissions from ships are to be reduced?

Q Describe with the help of a sketch, an aerobic sewage treatment plant:

a) State the effect, if any, of change of temperature & regularity of flow on the system.

b) Explain the significance of Biological Oxygen Demand.

Q Describe the type of pump that would be installed in a hydraulic system for deck machinery:

a) Explain the possible causes of the contamination in a hydraulic system.

b) Describe the likely results of contamination

c) Explain how contamination is monitored.

Q a) Explain why centrifugal pumps cannot handle air or vapours to effect priming yet turbo- blowers operating on the same principle can.

b) If a vessel is fully laden, how may it be ascertained that the fire pump pinning arrangements would operate satisfactorily in the ballast condition.

c) Explain a method of priming suitable for a centrifugal pump.

Q a) Sketch a simple cross section through a single stage centrifugal pump with a fully shrouded single entry impeller, name the components of the pump & indicate the direction of fluid flow.

b) Describe:-

i. The function of the impeller and how suction is created by it.

ii. The function of the volute casing.

iii. State the material of each component of the pump.

c) State the suction lift that may be expected.

d) State why some centrifugal pumps have:-

i. A double volute casing

ii. A diffuser ring

Q Sketch & describe the hydraulic system for a Framo pump. State the normal maintenance required for the pump?

Q Sketch & describe a main lubricating oil pump. Which are the clearances that are required to be checked and why?

Q a) i. Sketch the pump characteristics of a typical centrifugal pump.

ii. Explain how these characteristics are obtained.

b) Some engine rooms circulating pumps of the centrifugal type are arranged for variable speed operation. Sketch the characteristics curves for such a pump indicating the effect of varying speed.

c) State the reasons for using pumps of the type referred to in (b).

Q (a) Sketch and describe a gear type pump indicating the flow of fluid.

(b) State the materials that gear type pump components may be manufactured from.

(c) Specify THREE applications that are suitable for the employment of gear type pumps.

Q With reference to independent emergency fire pumps:

a) State 3 areas where they are commonly installed and give reasons why

b) Describe with the aid of a sketch an air pump or primer used to initiate suction when the fire pump is situated above sea water level.

c) State the suction lift which would be expected from a single stage pump system.

d) State how the capacity of the fire pump should be tested.

e) State how it can ensure that the pump is kept in good working order.

f) State the precautions which must be taken in sub-zero temperatures.